Zhaogou Fm
Type Locality and Naming
It was named by Li Xingxue in 1954. The naming section is located in the area extending from the Toudaogou Gully to the Erdaogou Gully, Gucheng Pagoda, Shiguai District, Baotou City, Inner Mongolia.
Synonym: （召沟组）
Lithology and Thickness
Lower part is composed of an alternating layer of grey-white and grey-green sandstones and pebble-bearing sandstones in association with grey sandy shales and carbonaceous shales, intercalated with conglomerates and coal beds. Upper part represents an alternating layer of brown-grey oil shales, grey-black shales and grey-green sandy shales in association with grey and grey-green medium-, and fine-grained sandstones, intercalated with carbonaceous shales and coal beds. Its total thickness is of 920 m. And the formation represents a major coal-bearing horizon in this region.
Relationships and Distribution
Lower contact
In the Shiguai area of Baotou City its basal part with a layer of grey-white thick-bedded conglomerates and pebble-bearing sandstones is also in a conformable contact but with the underlying Wudanggou Fm
Upper contact
In the Shiguai area of Baotou City its top part with a layer of brown-grey oil shale is in a conformable contact with the overlying Changhangou Fm
Regional extent
It is distributed in the same region where the Wudanggou Formation is distributed. Both the lithology and thickness of the formation are changeable from region to region. In the Anggen area of Wulate Central Banner the formation is composed mainly of medium-, and fine-grained arkosic quartz-sandstones, conglomerates and pebble-bearing sandstones, intercalated with mineable coal beds, with a thickness of 338 m. And in the Yingpanwan area of Wulate Front Banner the formation is composed largely of thick-bedded conglomerates, intercalated with sandstones and sandy shales, with a thickness of over 520 m.
GeoJSON
Fossils
It yields plants with their important members comprising Coniopteris hymenophylloides, C. szeiana, C. tatungensis, Czekanowskia murrayana, Cz. Rigida, Eboracia lobifolia, Elatocladus subzamites, Equisetites lateralis, E. furganensis, Ginkgoites xinjiangensis, Hausmannia leeiana, Neocalamites hoerensis, Nilssonia nipponensis, Phoenicopsis augustifolia, P. rigida, Pityophyllum lindstroemi, Podozamites lanceolatus and Sphenobaiera angustiloba.
Age
Depositional setting
The formation is predominated by the lacustrine-, and swamp-facies deposits, in association with fluvial deposits.
Additional Information